General ⇒ How to require a variable to be set?

[sschuberth]

Hi,

I'm currently writing my own little style (sty) file for the title page of my thesis (article document class). I'd like to introduce several new commands / variables, e.g. "\thesistype", that need to be set when using my style. It seems I somehow need to introduce these new required variables to LaTeX, even though I'm not setting them in the style file, but just using / inserting them via "\@thesistype".

So my question is, how can I tell LaTeX that my style requires a variable / command named "\thesistype" to be set, without actually setting it? The "\(re)newcommand" / "\providescommand" stuff only seems to be suitable if I'd like to actually set the value of the variable / command, not just check for its presence.

I've seen constructs like

Code: Select all

\def\department#1{\gdef\@department{#1}}
\def\@department{\@latex@warning@no@line{No \noexpand\department given}!!!\noexpand\department!!!}

but a) I don't understand how this works (Could some one explain it to my?) and b) I'm not sure all if this is the correct / recommended way to achieve what I want.

Thanks in advance.